Objectives: To develop, implement, and maintain a comprehensive information system for collection, storage, manipulation, retrieval, analysis and reporting of data pertaining to carcinogenesis bioassay studies. In so doing, to create and maintain a file of data about (a) substances on test in the Carcinogenesis Program, (b) experiments and related experimental design in bioassay studies, (c) diagnoses of animal deaths from suspected carcinogenic agents on trial, and corresponding control groups. Standard taxonomic, system-operational, systems design, computer programming, and statistical computing techniques, as well as the NIH/DCRT hardware and software environment have been used in the development of the system. A chemical data subsystem is in operation and contains relevant data on substances under investigation. It can be used for quick response upon inquiry.